Wireless sensor networks promote intelligent transportation, intelligent medicine and environmental monitoring, but the limited power of sensor nodes limits the development of these applications. In order to effectively save data transmission energy in wireless sensor networks, an event-driven output feedback control mechanism with discrete time invariant system is proposed. Firstly, the transmission strategy is derived by using approximate quadratic function. And the proposed transmission mechanism can be used to balance the actuator and wireless transmission rates. Secondly, the output feedback gain matrix is designed, the upper bound of the approximate quadratic function is calculated, and the corresponding output feedback controller is designed. Finally, the simulation results show that the energy consumption per data transmission is only 50 nJ/b. The proposed transmission mechanism can extend the battery life of sensor nodes by about 20% by comparing with the traditional periodic transmission mechanism, which verifies the validity of the theoretical results.